Cable tensioning mechanism



' F. H. TAYLOR CABLE TENSIONING macnmsm Filed July so, 1942 2Sheets-Sheet 1 Aug. 31, 1943. F. H. TAYLOR 27,328,364

I CABLE 'I 'ENSIQNING MECHANISM Filed July so, 1942 2 Sheets-Sheet 2- 3:WWW EA/v/r/i FWLOE Patented Aug. 31, 1943 q UNITED STATES. PATENT OFFICEi 7 2,328,364 i i a a CABLE TENSIONING MI'JCHANISIMI mm 11. Taylor, NewYork, N. Y., assignor'to Lehigh Structural Steel Company, New York,

N.Y., a corporation of Delaware o Application July so, 1942, Serial No.452,978

3 Claims. ,(01. 265-4) This invention relate to a cabletensioningmechanism, and more particularly to an appa: ratus operable incombination with the guy cables of radiojtowers andsimilar structuresforplacing the cablesjunder properpredetermined tension.

While the invention is applicable for use 'in tensioning guy cablesassociated with any types of structures, it is particularly effectivefor use in tensioning the guy cables of thetypes of radio towers now inuse, such a tower being oifthe single vertical unitary type resting on asingle support and held in vertical position by guy cables anchored attheir lower ends to the ground and connected at their upper ends to thetowerv in a common horizontal plane. Two ore more sets of such cablesare frequently employed with each it too greatly increases the latitudeof swinging movement of the tower on its base. i

.The: proper tensioning of theguy cables provides'for a proper anddesirable limited movement or the upper end of thetowerandadvantageously cushions such movement without unduly straining thecables and causing them 'to part. Heretofore, it has been necessary todetermine when the proper tension has been placed in a cable .byemploying relatively expensive dynamorneters and the desiredresults'havebeen accomplished only under ratherdiflicult conditions. f It h o An important object of the present invention is. to provide novelmeans operable in combina tion with a guy cable or the like whereby thecable may be placed .under proper tension very quickly and easily,whereupon the apparatus may be quickly removed withoutdisturbing thecable. A further object is to provide a novel arrangement of partswherein simple conventional devices may be employedhin the combinationtopermit quick assembly or the parts and easy man- .ualtensioning of theycable to the proper point. flAyfurtherobject is tofprovidesuch an organization jof the parts zwhereinthe apparatus is capeble 01 being mountedwithrespect to the cable without disturbing the normal operable"position of the cable either in "attaching the'device or removing it, orin performing the: operation of ten sioning the cable. y

A further object is to provide an apparatus of the character referred towherein substantially the entire length ofthe cable is placedundertheproper tension while being held bythe apparatus almost exactly in itstrue normal operative position,after which the guycable can be securelyanchored with the exact desiredfltension maintained therein.

A further object is to provide a, tensioning mechanism which isconnectible to the cable at a point adjacent its lower end and whichserves temporarily as the means for holding the cable in its properposition while introducing the ilesired degree of tensioning therei nto,after which the lower extremity of the'cablemay .be quickly connectedand tightened with respect to its anchoring means 1 while holding thecable under proper tension, theweight of the partsemployed with relationto the angularity of the cables be-. ing such that the resultantdownward vertical forces acting on the cable are so negligible that thecable moves an inappreciable distance at its point of connection withthe apparatus when the latter is removed.

A furtherlobject is to provide means tempo- I rarily connectible withthe cable for properly tensioning the latter with the tensioning meansengageable with permanent simple anchoring devices which are left inposition after the appa-.

Other objectsand' advantages of the invention will become apparentduringthe course of {the i following description.

..In the drawings I. have shown two embodinients .of the invention. Inthis showing Figure ,1 is a front elevation of the apparatus in positionona guycable, i I

Figure 2 is a section on line 2- -2 of Figure 1, Figure 3 is an..end.elevation looking in the same direction as Figure 2;.

Figure 4 is a section m me 14-4 of Figure 1, Figure 5 is a frontelevation: of a modified. and preierredtype of apparatus, and f i Figure6 is a side elevationof the same. I The form of the invention shown in.Figures 1 to 4 inclusive generally; illustrates the principles involvedin th invention and has been shown in. what might be termedsemiediagrammatic form. The-radio toweror other structure in connectionwith which the tensioned cables are employed has not been illustratedsince it forms no part of the invention and the latter is applicable toany cabl or similar device which it is desired to place underpredetermined tension in a predetermined position. Referring to Figures1 and 4, the numeral I!) designates a guy cable of a radio tower or theikg' which it is desired to plate under predetermined tension the upperend of the cablebeing connected to the tower or other structure in aconventional manner and the lower end being fixed with respect to anysuitable type of ground anchor! I For corp nesting the cable withrespect to the ground anchor a turnbuckle I2 is employed, thisdevicecomprising the usual rotatable body i3 and threaded rods is and I5mounted in axial align ment and oppositely threaded in the ends oi thebody l3. The upper end of the rod It is provided with an eye it throughwhich the lowerencl of" the .cablenes es the .ettmmi raf h amerat he mah, hm emmehod of h cable as t L vvThe ew rt 'eedpftt e y e pr vided witha yoke l8 bolted as at l9 t'othe a q nd an or L, v .c i

balancing member 'or cross barn. forms the el ra t Q the r e aeratewhichjis e neoted to or eng ageable with the cable Ill. The

' balancing ,rhernber may 'of 'channel section "as awarenes i di%-During the s'ioningfoperation to'be referre to, the member is fried withrespect to the cableby alny sui'table typeof clamp Force is applied tooppos'itev endsofi'the member 20 and for this purpose siiitlablesets or'bldclgsfaind tackles, respectively indicated as swhoie by the numerals2! and 22, e mi ii la t I The block find taclil set 2] comprises upperand lower sheet/enters 23 land 24 the former of which is oonriected'asat 25 to the balancin member in and the latter of which is cdsheeteda'sfaft. 26 toan anchor 21 ;v likable 28 is suitably 'c' oiliventionallypassed around the wheels of the block's23 and 2'4 to provide the desiredleyeraig'e ull 'rna'y bereadilytranlsfree end of the cable 2 8, Figure'2 and indicated The block and tackle set 22 jeoiripris'es upper alowe'r' sheave 'blo'eks :3 I; and 132 the former of which is, connet da'sfat133 to, the adj acent end oi the balar'idirig me berj ZU.Thef'pointjo" thine'ction f. he nei he w f n ins member T20 ispreferably spaced a substantially fgre'jaterdistance from the cabljejlflthanthe fpbint of "connection of the'members '25 and .1. Thisarrangement provides substantially greater lie to employ concreteblook'of desired weight.

:During the tensioning of t he apparatus, as'will be described, theweight SSreSts'upon'theTf-Sur rounding surface of the-ground and theproper tensioningpi the cable is reached when the t f ea ie lfiek Iprovided with other hairpin weight is lifted just clear of the ground.This is done with the lower end of the cable [0 free, and when thedesired tension has been reached the turnbuckle I2 is applied andtightened. This operation will be more fully described later.

The form of the invention shown in Figures 5 and 6 is similar inprinciple to that described but is preferred because of its simplicityand compaotness and for other reasbns which will beeonieapparent.Referring-to? Figures 5 and 6 it will be noted that the cable and theelements associated therewith for anchoring it with reof the inventionpreviously described, and such partshavefbeen ih'dioated by the samereference him 1, .h

* been more particularly illustrated as being in the a-l's. however, theground clamp H has form of a plate embedded in a concrete anchor blockindicated by th numeral 45, the lower end of theplate being turned as atH to secure a more perfect-permanent anehoringof the plate with respecttotl ie'blbck. The plate i I also has been 'shownin 6 or the sets or theguy cahresjem'picsyed. I

"A balancing member "'41, i similar'to but shorter than the member itpreviously 'de'sbribed, is pro vided with a damp rs for T int;itwith'resp ectfto 'tl 'ie'cable l8. heme-Inner 47Tnayfbeofjany"de-'sired section a d rsshowh in '6 being "or angle section, The member 37'may bejprovi'ded' mates "4e tliese plates and therinerhber tr maybe aertures as fat-5e to "reserve connec'tin'gfel'efner'its 51 1a '52as-sedated with block and teem-e assemblies respectively "indicated asawhole'byftlienumerals t3 and The "asseme ibly '53 tam-prises upper andiewersheave tracks 55 and as around t ew eeis of whichis eehventitbypassed a r t1 o provide"thei'desir'e'd leverage, 7 One end of thefcabl'e l"rnay' be coniiet'edfto thelowerblock}?while-the other end;indicated by "theiium'e'reil 53, is adapted, to be pulled by an operatort'o"movethe eor'respohdih' end or "the "'balarioin'g' memherf ndownwardly. The e hhectibs element-t1; is co'n'he'eted to "the mode 155,while "the "b'lo'ckf t is prlivi'dedj with a h'ookhll engage'able"withihe 'lfoop'of a hairpin ahhOWfi Weinbddbdifltli block 45. "Thevasterribly 58"" merin uea ama rower Z "the lowerfo'fjfxvhi'h is 19 j le"wi r '64! also erhbeddedfin block 45. "A 'ablefiE' pass-es around "theof the blocks 6i and 62 andha-s a free I to be f pulled by'theoperator"tombvejthe com Ch n me ,1 t v o'a'rr'i' d by the "casing hr"the fdynamoine ier aha and n Figure 5 as having a second any 'ed' bythe numeral 5'6 and fleeting element 52. The dynamometer 61 mayoperation of the'fapparatus is'as follows: Itlwill beapparent in-theform of theinventiorl shown i in i Figures 1- to 4 inclusive that :thepointof connectionkof the turnbuckle I 2 with the be an' ordinary springscale of sufliciently heavy 1 capacity to take care of the forces whichit is called upon to withstandiancl tomeasureL anchor rll .andthe point.oflc'onnection. of the' sheave block :24 withithean'chor 21 he inacornmon plane with the connectingrelement 25,cable alsoeisgprovided inthe formof zthecinvention shown in Figures'E: and 6 exceptthat bothsheave assemblies are anchored; to the block. 45. instead of,employing'the weight 3911s the means :for. determining the maximumtensioningforce'; All of. theanchoring points for the sheave assembliesand for the cable. H1 in Figure .5 lie in acommon plane corresponding tothat referred to. above.

It, will .be apparent, therefore that: the attachment of; either form ofthe'invention to the cable results in the use of ,the present. devicefor sup-, porting; the-: cable, exactly in the position whichitgwilkoccupy later when the apparatus is re:

moved. This is important since any. shifting-of tl'ieypoint in the cable10 engaged by the clamps ZI or 48. when the deviceis removed wouldresultin reduction in the tensioning force of the c l h in. m llnpusing theform, of the invention .shownlin Figure 1, the apparatus will be set upwith the support 38 arranged in such position thatethe portionofthecable 36 between the block 32 and pulley 31; will lie inia common planewith the cable. I and the line of ,force being applied through thesheave assembly 2|. 'ThlSBOm-II IOH plane obviously will includetheconnecting point la between the turnbuckle, I2 and'anchor ll. As soonasthe parts have been set up as described, the operation of tensioning thecable may begin. This operation is initiated, of course, with the weight39. resting on the ground. The weight 39 may be of any form and ispreferablya con crete block of predetermined v weight in accordancewiththe desired tensioning of the cable! and in accordance with the relativelever lengths of the portions of the member 20 on opposite sides of theline of the cable l0. i v

. The operators will pull downwardly'on the free cable ends 30 and 35 topull the balancing member 20;downwardly to increasingly tension theportion of the cable between the member 20 and the mast or tower beingerected. Care will be taken to maintain the member ZOperpendicular tothe cable. Whenthe exact point isreached at which the cable I0 istensioned to its predetermined extent, the upward forcebeing exerted onthe Weight end of the member 20 will equal the Weight 39 and the-latterwill start'to move vertically from the ground. At this point furtherpulling onthe cables 30jarid 35 will be stopped,

the proper tensioning of the cable having been reached between themember 20, and the tower. Theturnbuckle l2 will nowbeapplied, or will bethetightening'of theturnbuckle will continue untilitreache's apoint atwhich the tension-in the cable line between the clamp 2i and the-anchorI, I veryislightlyexceeds the tension of the cable l0 between thebalancing member and the tow er. This will be indicated by a slightdownward movement of the weight 39, the lever arm of the member 20 towhich the member 33is connected providing for an appreciable loweringfof the weight 39 when tension ofthelowerend of the cable very slightlyexceeds the tension i of the upper end thereof; t The entire link of thecable i0 and :associated elements 'will now be approxi mately uniformlytensioned atthe proper-point;

ThelinesSll and35 now. may bereleased and theclampZl removed;whereupontheconnecting ele-' ment 26, may be released frem'the hookofthe anchor-21.

It will be obvious that the removal'of the apa paratus in-the mannerreferred to. will leave the cable ID in exactly the same position aswhen the tensioning operation had been completedxby the pulling on thelines and 35. .All forces will have been applied in'the commonplanereferred to and along lines parallel to thecable ,I 0, and accordinglythis cable will remain, after removal of the apparatus, in the samepositionas before and will be properly tensioned. The same opera tion,of course, is performed for each of the guy cables. c

The operation of the form of the invention shown in Figures-5 and 6 willbe substantially the same as in the form previouslyadescribed. Forces:will be applied alonglines parallel toKthe cable [0 and in the plane ofthis cable, .as: in

the previously described form of the 1 invention. Therefore, the cablewill be bothproperl y tensioned and pulled to the exact. positionwhichit will occupy after'the apparatus is removed. The only :differenceinprocedure in thexform of the invention shown: in Figures 5 and 6 liesin the fact that instead of'exertingthe forces until \a weight hits fromits supporting surface, the forces are applieduntllthe dynamometer 61in.-

dlcates proper reading. :At this point the pull r of the devicepreviously described. It also will .be apparent that. the, two.hairpinanchor bolts and 64 'areleft' permanentlyfin the block I ll!forifurther use in retensioning the cablefif necessary,-,or for use inreplacing a broken cable. The distance between the anchors .II and 60equalgthe distance between thecable lllandthe point of connection of theconnecting element 5| with the openings 50. Similarly, the distancebetween the anchors ll and, coincides with the distance between thecable. I and the openings 59 for the connecting. element 52.

. therefore, the balancing member 41. and its astightened if ithas been;previously applied,

sociated elements are designed forvcooperation wlththe anchor 60 and 64these elements in the blocks associated with each of the anchors l 0 forthe tower bearing the same arrangementwith respect to the variousanchors H as described aboveso that the tensioning. apparatu is mov-Obviously,

one end to a given structure andhas means at its other end to beconnected to an anchor, a

tensioning apparatus comprising a balancing member having means fordetachably connecting a it to the cable in a position approximatelyperpendicular thereto at a point spaced from the last named end thereof,a pair of block and tackle assemblies connected to said balancing memberat points spaced IIIOm said clamp on opposite sides thereof and arrangedto exert forces on said balancing member in the direction of said anchorin lines spaced from and parallel to a line between said detachableconnection and said anchor, each of said assemblies having a flexiblemember provided with a free end to be pulled to generate the forceapplied to said balancing member, one of said assemblies having meansfor indicating when the portion of the cable between said structure andsaid balancing member has been tensioned to a predetermined extent, and

take-up means in the portion of said cable be tween said balancingmember and said anchor for tensioning such portion of the cable after.

the first named portion of the cable has been tensioned to saidpredetermined extent.

8. In combination with a cable to be placed under tension, wherein thecable is connected and an anchor, the lower end of said cable havingmeans for connecting it to said anchor, at tensioning apparatuscomprising a balancing member, means for detachably connecting saidmember to the cable in a position approximately perpendicular theretoand at a point spaced from the lower end thereof, a base structure bywhich said anchor is carried, a pair of anchors carried by said basestructure at points spaced from said firstnamed anchor, and a pair offorce-applying devices connected at their upper ends to said balancingmember on ouposite sides of said clamp and detachably connected at,their lower ends to the respective anchors of said pair, the points ofconnection of said force-applying devices to said balancing member andto said pair of anchors being in a common plane with the predeterminedline of the portion of the cable between the detachable connecting meansand sad first named anchor, said force-applying device being arranged totransmit downward forces to said balancing member in lines parallel tosaid predetermined line of said portion of the cable, one of saidforce-applying devices comprising means for indicating when the portionof the cable above said clamp has been tensioned to a predetermineddegree, and take-up means in thecable between said balancing member andsaid first named anchor.

9. The combination defined in claim 8 whereto generate the forcetransmitted to said bal-,

ancing member.

FRANK H. TAYLOR.

